Drift



' Aug. 17, 1943. F. J. WOODRUFF 2,)

DRIFT Filed April 7, 1942 'ATTORN s.

Patented Aug. 17, 1943 T "OFFICE DRIFT Francis J. Woodrufi', Detroit,Mich, assig'nor of oneilhalf to John Thomas Gilmer, Detroit, Mic wApplication April 7, 1942, Sean No. 438,017

2 Claims. 7 (01.254-404) This invention relates to drifts of the typeused by mechanics, commonly known as key drifts, and the principalobject is theprovision of a drift of new and novel character whicheliminates certain disadvantages of conventional types of such drifts.

Objects of the invention include the provision of a drift which whenemployed for removing a gear, pulley or the like from a shaft it Willnot cause the gear or pulley to cock on the shaft and thereby resistremoval therefrom; theprovision of a drift of the character described bythe use of which the pressure applied by the drift to the piece to beremoved thereby may be applied in such a mnner as to reduce the bendingforce on the piece as compared to a conventional drift; the provision ofa drift of the character described so constructed as to eliminate thetendency of conventionaltypes of drifts to slip out between the partsbeing separated thereby; and the provision of a drift of the characterdescribed that is double wedge shaped in conformation whereby to enablecertain advantages to be obtained thereby and certain disadvantages ofconventional types of drifts to be dispensed with.

The above being among the objects of the present invention the sameconsists in certain novel features of construction and combinations ofparts to be hereinafter described with reference to the accompanyingdrawing, and then claimed, having the above and other objects in view.

In the accompanying drawing which illustrates suitable embodiments ofthe present invention and in which like numerals refer to like partsthroughout the several different views,

Fig. 1 is a perspective view illustrating a pair of pulleys mounted on ashaft and illustrating the use of a drift constructed in accordance withthe present invention to remove one of the pulleys from the shaft and adrift constructed in accordance with the present invention to remove akey securing the other of the pulleys to the shaft;

Fig. 2 is an enlarged perspective view of a lefthand drift constructedin accordance with the present invention;

Fig. 3 is a transverse sectional View taken on the line 3-3 of Fig. 2;

Fig. 4 isa perspective view of a righthand drift 7 constructed inaccordance with the present invention Fig. 5 is a transverse sectionalview taken on the line 5-5 of Fig. 4;". a

Fig. 6 is a perspective view of a combined right and left hand driftconstructed in accordance with the present invention; and,

Fig. 7 is a transverse sectional view taken on the line 7-1 of Fig. 6.

Drifts of the type herein under discussion are forms of wedges usuallyhaving a constant width and varying in thickness. They areconventionally formed from steel and are usually of hardened character.They are conventionally employed between a pair of machine parts whichit is desired to separate from one another and in employing the same thesmallend of the drift is inserted between the parts and pressure isapplied to the thick end of the drift, usually by a hammer or equivalentmeans, thus to force the drift between the parts and cause them to bewedged apart. Such drifts are commonly called key drifts for the reasonthat one of their major uses is to remove the driving keys between ashaft and some part fixed to it for rotation, the keys in such caseusually being provided with a head projecting outwardly beyond thesurface of the shaft between which and the 'part mounted on the shaftthe drift may be inserted .and. driven. Such driftsalso find wide use inremoving pulleys, gears; or like objects from shafts, this beingconventionally accomplished by inserting and driving the drift betweenthe hub of the pulley, gear, or the like and some parts fixed to theshaft and providing a face lying in a plane perpendicular to theaxis-thereof. p

In the past it has been conventional practice to form such drifts ofrectangular cross-sectional configuration. As a result, if the partsbetween which the drift is forced are worn or battered the wear orbattering has usually occurred radially outwardly from the surface ofthe shaft on which they are mounted with the result that there is atendency for the drift to be displaced radially outwardly between theparts upon pressure being applied thereto before a sufficient amount ofpressure can be exerted longitudinally through the drift to separate theparts axially of-the shaft. Where this condition exists the removal of apart from a shaft often becomes an exasperating job in view of the'difficulty inmaintaining the drift in that position to which it isrequrecl to be maintained'in order to effect its purpose. If the partsbetween which the drift is positioned are provided with surfaces whichare not worn or battered and lie in planes perpendicular to the axis ofthe shaft; then there is a tendency for the driftto exert its pressurebetween the radially outward parts of such surfaces andparticularlywhere the part to be removed is a gear or pulley having arelatively limited axial length or dimension, the pressure of the drifthas a tendency to cock the gear or pulley on the shaft and to cause itsaxially outer edges to dig into the surface of the shaft and resistmovement thereof on the shaft under the force of the drift.

The disadvantages above described in connection with drifts ofconventional construction is obviated in accordance with the presentinvention by so forming such drifts not only are they wedge-shapedlongitudinally as in conventional drifts but additionally they are morewedge-shaped in transverse section. In other words they are similar toconventional drifts in being longitudinally tapered to wedge-like form;but additionally the transverse dimensions of one of the side faces ofthe wedge: are uniformly less over the length thereof as compared to thecorresponding dimensions of the other side face of the. wedge,thusforming the drifts. with one edge formed by the juncture of twosurfaces dis.- posed at less than 9 'degrees with respect to each other.

With a drift formed in accordance with. the present invention and asabove described,v that edge of the drift formed by the surfaces disposedat lessv than 99 degrees with respect to each other is. applied to. theshaft at the junction. between the shaft and the part to be removed.therefrom and then pressure is applied, to the drift in the usual way..Because of the angularity of the two sides referred to no pressure: isexertediby therdrift upon the part tov be removed from the shaft radiall-y outwardly ofv its point of contact with the: shaft and consequentlyno tendency to cock the part on the shaft occurs toresist removal ofthe'part. Furthermore, because. the line of contact: between the partsto be: removed from the shaft and the drift is limited to a lineintersecting the surface of' the shaft and perpendicular to the line ofcontact between the drift and; theshaft and: the drift is. free ofcontact with the'part: to beremoved: radi'aliy outwardly of such line ofcontact between the drift. and. the shaft, there is. no tendency'of' thedrift to slip radially: out:- wardly with respect to the part to beremoved from the shaft. Thus" two. of: the major disadvantagesofconventional drifts are obviated:

The same general remarks apply where: the drift is employed to-remove akey from between a shaft and a partmounted thereon as in such case the'sharpedge of the drift; that is, that'edg'e formed by the junction ofthe two surfaces 10- ca-ted at lessthan- 90- degrees with respectto eachother, is placed againstthe head of the key-at its point of junctionwith thebcdy-of the hey; this reducing any cocking tendency between thedrift and" the key to a minimum and elimihating the tendency of thedrift" to slip radiallyoutwardly of the shaft with respect to the headoflthe key.

' From the above it will be observed that it is the preferredpractice inthe. employment of a drift, constructediin accordance with the present"invention. to always place the sharp edge off the drift. against thepart which is. to be removed from another. part. and asclcse to the areaof junction. of, the parts as is practical under. the: circumstances.Actual practice-has demonstratedthat drifts constructed in. accordance.witl'rthe presentinvention are: much. more efficient, are longerlivedand permit themto; accomplish .thein intended result in a quicker andeasier manneror less than conventional drifts as heretofore constructed.

Drifts constructed in accordance with the present invention may berighthanded, lefthanded, or may be constructed to include a combinationof both. They are designated either as righthanded or lefthandeddepending upon which side I towards its longitudinal center line on oneface thereof, thus providing two sharp edges in a single drift.Referring now to the accompanying drawing, in Fig.. 1,, in order toillustrate the application of the invention, a cylindrical shaft isindicated at. 1-0 and as havinga pulleyend thereof and a pulley Mmounted adjacent the other end thereof. The pulley I12 is shown fixedfor equalI rotation with respect to the; shaft l0; by meansofakey Itreceived in the groove of key-way IS in the shaft {0 and inacomplementary groove or key-way (not-shown)- inv the bore of the pulleyl-2.. The outer end of the key 16- is provided with a. radially projecting, head 20. in accordance with conventional practice. Where a keysuch as: If is employed the pulley 1.2: will conventionally have asliding fit on the shaft l9- and will ordinarily be locked" in positionby means of. the key lBso that upon removal of the key t8. the pulley,IZma-y be removed from the shaft The pulley l4 may be assumed to havealight. press fit upon the shaft'l-fi and in such case. a. key such. asemployed in connection with the pulley I2. is neither necessary nordesirable unless the, pulley is to besubjected to extremely heavyturning. forces.

order. to remove the key it from the shaft ii and pulley 5.2 a drift isihsertedbetween the head' 25] of the key. L6 and thehub of the pulley I2andthedrift is. driven as by means of a hammer between theseparts thekey 15 thus being: forced. axially along the shaft frombetween the shaftand the pulley 12;. Where it. is desired to remove a pulley such as Mfrom. the shaft m the shaftlwill' usually: be provided with a collar asEd fixed to the shaft, at onev side ofthe pulley or be prOVl'd'ed with aradial shoulder corresponding with the end surface of the sleeve 25 andbetween which and the hub" of the" pulley M the small end of thedi'iftmay be inserted as shown and driven-homeas by means of a hammen 22to cause the pulley l4 to'bedisplaced axially along the shaft 02- If inthe caseshcW-nin Fig; l the drift is aconventional rectangularlysectioned drift and the inner radially disposed face of the head 2-0 of;the key 5 5 isworn or battered it will be ap preciated'; slit in drivingthe drift between the head of the key and the pulley l2 there \v-illbeatendenoy for the-drift to slip": radially outwardlysbetween; thev partthat it. isv intended to sepa'- rate, On the other hand, if the:surfaces referred to: are; square. then; there. willi he a! tendency forthe dr t to bear against tlieradi'allyouter edge of-the-inner face ofthe head=29of the key [6 and to; force the axially outer'radiailyinner:edge: of the key 55 into the metal at the bottomrof thekey-wayiii-thusto dlg' into;s-uch metal and to increase the resistanceto its removaL.

Inthe: case ofthe; pulley M if the drift-eml-Z mounted on one contactwith the surface of the shaft ed is a conventionally rectangularsectioned the cooperatingfaces between which the drift is received arenot worn or battered so as to engender slipping out of the drift, thenthere will be a tendency of the drift to bear against the radially outeredge of the hub of the pulley it and to cause the pulley to cock on theshaft 59 so that its axially outer edge will tend to dig into thesurface and resist removal.

The drift 38 indicated in Fig. 1 between the pulley id and the sleeve 24is a lefthand drift constructed in accordance with the present inventionas illustrated in greater detain in Figs. 2 and 3. Referring to thesefigures it will be appreciated that thedrift 3%! there shown is formedfrom a piece of metal, preferably steel and preferably hardened, is ofan equal width throughout its length which is preferable but notnecessary in the particular form shown, it tapers, in the particularform shown, uniformly in thickness from one end to the opposite endthereof, and in accordance with the present invention the thicknesstapers in transverse section from one side thereof to the opposite sidethereof so that the lefthand face thereof as viewed in Figs. 2 and 3 isuniformly of less thickness, or of less dimensions transversely -of itslength, throughout its length than the thickness or correspondingdimensions of the righthand face thereof at a corresponding position inthe 7 length of the drift. The bottom face 32 drift 3! is located in aplane perpendicular to both side faces 34 and 36 but the angularitybetween the side face 38 and the top face 33 as viewed in cross-sectionand as illustrated in Fig. 3 is less than 90 degrees so as to form asharp edge do. This feature imparts a'trapezoidal section to the drift.Ihe angularity between the faces 36 and 38 insectional view may, ofcourse, vary between greater or lesser limits, but if arranged between75 and 80 satisfactory results of the will usually be obtained.

When employing the drift 30 for removing a pulley such as I 4 from theshaft such as ID as illustrated in Fig. l, the face 36 is positioned inH1 between the hub of the pulley l4 and the sleeve 24 with the shar edge40 bearing against the hub of the pulley M, in the same manner aspreviously explained and for the same purposes. Because of the sharpedge 40 the pressure exerted on the pulley M tending to force it axiallyof the shaft It is exerted and a minimum radial distance from the axisof the shaft I andpulley M and consequently exerts a minimum tendency towards cooking the pulley I 4 on the shaft l6. At the same time, becausethe sharp edge provides substantially the only line of contactbetweenthe drift and the pulley' l4, it eliminates any tendency of thedrift 30 to slip radially outwardly of the shaft HJ along the inner faceof the hub of the pulley l4.

The drift 44 illustrated in Fig. 1 between the head 28 of the key I6 andthe hub of the pulley i2 is a righthand drift such as illustrated inFigs. 4 and 5. The drift 44 is identical to the drift 38 in all respectsexcept that in cross-sectional configuration it is tapered in anopposite direction. In other words the drift 44 includes a fiat bottomface 46 which lies in a plane perendicular to the planes of the sidefaces 48 and i! and out of parallelism with the top face 52. This drift44 being a righthand drift the righthand face 58 is of less thicknessthan the lefthand face as, just the reverse from the corresponding facesas and 36 of the drift 3-), and so as to form a sharp edge 54 along thelei'thand edge of the drift as shown. In its application between thepulley i2 and head of the key l6 as in Fig. 1 its side face 68 is placedin contact with the radially outer face of the key 56 between the head26 and the hub of the pulley l2 with the sharp edge 54 th reof engagingthe axially inner face of the head 23 at its poi junction with the bodyof the key it as will be readily appreciated.

In Figs. 6 and 7 a combination drift embodying both features of theabove described drifts 3G and 44 is illustrated and in effect it takesthe same form as would occur if the drifts 36 and if were positioned inside-to-side relationship with the bottom surfaces 32 and thereofarranged in the same plane with the narrow edge surfaces 34 andi!)thereof in contact with each other and with their respective oppositeends in flush relationship with respect to eachother, except that inthis case it would b formed in one piece. In other words, the driftindicated generally at 6B in Figs. 6 and 7 includes a plane bottom face62, opposite side faces 64 and 66 arranged in parallel planesperpendicular to the plane of the face 62 and each having equal verticaldimensions uniformly increasin from one end of the drift towards theopposite end of the drift. The top face of the drift 6!] in this case ismade up of two surfaces 68'and 10, each occupying one-half of the areaof such upper face. The angularity between the side face SA-an-d the topsurface 68 in cross-sectional configuration asillustrated in Fig. 7 isless than 90 degrees so as to form a sharp edge" and in a similar mannerthe angularity between the side face and the top surface portion 10 incross-sectional configuration as illustrated in Fig. '7 is less thandegrees so as to form the sharp edge'f. Thus the righthand side of thedrift shown in Fig. 6 is equivalent to the lefthand drift 30 illustratedin Figs. 1 and 2 and the lefthand side thereof equivalentto-therighthand drift illustrated in Figs. 4 and 5. It will be readilyappreciated that the drift 60 may be used in any case where either thedrift 3!] or the drift may be employed.

Having thus described my invention, what I claim by Letters Patent is:

1. A key drift comprising an elongated metal member the side edges ofwhich are substantially parallel to each other, said member increasingin thickness from one side edge thereof toward the other side edgethereof, the thicker of said side edges being flat, and one of the sidefaces being perpendicular to the plane of said thicker side edge, saidmember also increasing in thickness from one .end thereof toward theother end thereof.

2. A key drift comprising'an elongated metal member having fiat sideedges arranged in substantially parallel planes and a flat side facearranged substantially perpendicular to the planes of said side edges,the remaining side face of said member being formed to present two flatsurfaces intersecting one another medially of the longitudinalcenterline of said remaining face and forming a re-entrant angle betweenthem, said member increasing in thickness from one end thereof towardthe other end thereof.

FRANCIS J. WOODRUFF.

